If you fall asleep at 8pm and wake up at 4am with 8 hours of sleep why do you feel extremely tired by 10am, but if you go to sleep at 11pm and wake up at 7am you can stay up all day without feeling very sluggish? Does it have something to do with waking up while it’s still dark?

Question

If you fall asleep at 8pm and wake up at 4am with 8 hours of sleep why do you feel extremely tired by 10am, but if you go to sleep at 11pm and wake up at 7am you can stay up all day without feeling very sluggish? Does it have something to do with waking up while it’s still dark?

In: Biology

Answer 1

It all depends if you wake up during one of your REM cycles or after REM cycle. On average you go through 3-5 REM cycles per night. And If you wake up in the middle of cycle you will feel like shit, doesn’t matter if you slept 4 or 8 hours…same if you wake up after cycle you will feel rested.